In tangentially related news, I spent some quality time with this little lady in the garage yesterday:

She was perfectly amiable. I didn’t touch her, but I sat next to her for a while and at one point gave her a nudge with the corner of my phone to see how she’d react. She just shifted over a little.

At no point did I crush, squash, dismember, or mutilate her. When I checked back later she’d moved off into some dark recess.

It’s a little weird to navigate this boundary. Until recently I was a squash-all-black-widows-on-sight person, and this behavior of mine would have seemed thoroughly irrational. It still feels odd, and subject to an undercurrent of lingering arachnophobia.

On an evening very similar to the massive mayfly event of June 23 2012, the Mississippi River produced a massive radar echo as mayflies emerged from the water and became airborne. The mayflies were detectable on radar around 845 pm and reports in the towns and cities began rolling in of the swarming and piles of mayflies. Numerous videos and pictures were circulating on social media, some of which are posted below as well.

The radar detected the flies about 845 pm, emanating from the river (the source) with echo values similar to that of light-moderate rain (35-40 dBZ). With a general south-to-north wind flow above the surface, the mayflies quickly moved north once in the air. As the flies dispersed moving north-northeast, they also gained altitude with some of the echo being detected as far north as Black River Falls and as high as 2500 feet above ground.

By late evening, mayflies were swarming in La Crosse, La Crescent, Stoddard and points up and down the river. While the emergence of mayflies from their river bottom mud dwelling can occur at various times through the warm season depending on the species, this particular emergence was that of the larger black/brown Bilineata species. The radar loop below shows the reflected radar energy (reflectivity) from 835 pm to just after midnight. The higher the values (greens to yellows) indicate greater concentrations of flies. Note how the swarm is carried northward over time.

Synchronized emergence of ephemeral adult stages is a beautiful thing. Mayflies (Ephemeroptera) are the best-known example, though there are others (like certain gall midges in Cecidomyiidae) that do it too.

They spend almost their entire lives as larvae. Then, on a particular night, they emerge as adults, mate, lay eggs, and die, all within the span of a few hours.

I wonder sometimes if the human affinity for dramatic stories that follow a certain narrative arc has its roots in this. The long, relatively slow build-up to a final climactic burst is something that has played out a million times in each of our evolutionary histories. Is it surprising that a story exhibiting the same pattern resonates emotionally?

The first thing you should know: The adult emerald ash borer is beautiful. Isolated in an artfully composed macro photo, its shimmering exoskeleton is breathtaking.

The second thing you should know: Unwittingly airlifted by humans into an environment from which it had been evolutionarily isolated, the emerald ash borer is simply following its God/Darwin-given imperative when it destroys the Northeastern ash forest.

The third thing you should know: The novel ecosystem that emerges from that destruction will not be a sterile lunar landscape. It will include many living things forming a deeply wonderful “nature.” Our descendants will walk through that landscape appreciating its non-human wonders even as some of them are aware of the role humans played in defining it.

The fourth thing you should know: Even so, something will have been lost.

This topic comes up every time I do a docent tour at the marsh. Much of the effort of restoring habitat is weeding out nonnative invasive plants. Remove the nonnative plants and you give the native plants a chance to survive. Help the native plants and you help the insects that co-evolved with them, and the insectivorous birds that co-evolved with the insects, and the parasites that live on all of them, and so on up and down and out through the multitude of layers that build up when life has a chance to operate in relatively stable conditions across evolutionary timescales.

A metaphor I’ve used to try to describe it is a piece of music. The organisms that co-evolve to form a natural community have built up over millions of years, gradually adding notes to a complex symphony that is rich and harmonious. Introducing a nonnative species in that setting is like bringing in a Jimi Hendrix solo in the middle of a Brahms concerto. It’s not that the Hendrix solo is bad. But it’s out of place, discordant. The other instruments can’t compete. The Hendrix solo gets louder, its amplification drowning out the gentle notes that had been providing its counterpoint. One by one, other instruments go quiet. Eventually the Hendrix solo may exhaust itself, continuing with the volume turned down. Things stabilize, and a new equilibrium is reached. But the overall musical landscape is poorer, less diverse, than it was before.

Over time it can build up again. The process of extinction and speciation continues. The emerald ash borer’s destruction of the ash forest is just one part of a much larger piece of music. There have been five great extinctions in the history of earth, and the fact that we’re currently engineering a sixth isn’t some huge tragedy, at least from a sufficiently detached perspective. It’s just the end of one movement, which will lead to the start of another, in which the music gradually swells as it plays toward its inevitable, much more distant, conclusion.

But on the much briefer timescale on which humans live their lives, it’s a loss.

This is not a tasty gummy sweet but a Jewel Caterpillar found in Amazon Rainforest. They are covered with sticky goo-like, gellatinous tubercles that provides protection from its predator like ants until they metamorphosise into winged moths.

Galls are the coolest things ever. Or at least the coolest things I’ve seen this week. I know nothing about this particular one, aside from that it’s growing on an elm tree and makes beautiful pink pouches of flower tissue spring from the leaves. Whoever lives in there is a lucky little bug!

I keep waiting for “bug season” to start, so I can get you all some fresh insect shots, but, alas, it did not get much higher than 30’F today. I think I’ll try to compensate with some super macro shots of butterfly wings. Here’s a magnificent eye spot from the wing of an owl butterfly.

You know what I love about this? The way the evolved pattern of scales perfectly imitates an actual eye’s three-dimensional shape. Look at the pattern of yellow scales, with the brown shadow on the lower-right side, and the bright highlight of white scales on the upper part of the pupil’s black scales. That gives you the eyeball’s curved surface. And surrounding the eye itself, the dark shading above and to the left, and the brighter edging below and to the right, with the part below bulging into the circle of the eye, creating the appearance of a socket.

That’s an artist at work, producing the illusion of three dimensions with pigments applied to a two-dimensional surface. Except the artist isn’t a creationist’s Artist. It’s evolution and natural selection. The startle effect of a moth suddenly turning into an owl’s face stops a predator for a crucial second, allowing the possessor of those spots to live to pass on its genes. And the gentle gradient of “better illusion = greater survival benefit” operates across millions of generations, until you get this.

I mentioned before that one of the things I enjoyed about Yulin’s beautiful I Didn’t Write This Ep. 2 (the one with Auden’s “As I Walked Out One Evening”) was the setting. They shot the video in Malibu’s Solstice Canyon, which I’d never visited before. It looked like there was some coyote brush (Baccharis pilularis) in some of the shots, but I wasn’t sure, and since yesterday was my once-every-two-weeks mega-commute via Malibu, I decided to check it out on my way to work.

I really loved it. There’s water in the stream year-round, and the riparian habitat along the main trail was super birdyish. I didn’t have my binoculars with me (which was just as well, or I probably would have been late to work), but the southern California nesting season is getting under way, so there was lots of singing. Yellow-rumped warblers, oak titmouses, California towhees, spotted towhees, and white-crowned sparrows were everywhere.

The upper slopes (which I didn’t have time to hike to) looked too xeric for coyote brush, but down near the creek there was a fair amount of it. It was more spindly than the plants I’m used to near Santa Barbara, and the seed heads on the female plants seemed a little less profuse; I suspect that’s because Malibu is warmer and dryer than where I live. There also was less coyote brush overall in the habitat; individual plants were scattered around, rather than occurring in extensive stands.

When I’m around coyote brush I always look for galls. There were relatively few Rhopalomyia californica galls compared to what I’m used to, but I found some that you can see in the middle row of photos above.

You’ll probably think I’m an idiot to feel this way, but I get choked up when I think about the midges that induce those galls. They spend most of their lives as tiny maggots inside the gall, feeding on plant tissue. Then they chew their way to the surface and pupate, their body liquifying before transforming into an adult midge, and then finally, on a particular cool morning, often a day or so after a rain, a bunch of them emerge together.

The females’ abdomens are already orange and swollen with eggs. The males mate with them and die; the females lay their eggs before dying a few hours later.

They live their whole lives for that one day. I’ve never seen a Rhopalomyia emergence in-progress, though I keep looking. Once I found a dead female a day or two after emergence, a sticky trail of eggs connecting her to the plant, dead in the very act of laying her eggs. Will my own life have a dramatic climax like that? Probably not. I’ll just get older and crankier, and eventually something will take me out. But that Rhopalomyia midge died a heroine, fulfilling the point of her existence in her final moments.

Besides the R. californica bud galls, I also found a couple of stem galls made by a moth, Gnomorischema baccharisella. You can see them in the bottom row of photos. A cool thing about these galls is how different the ecology of the gall itself is, compared with the similarly sized R. californica galls that grow on the same plant. The Rhopalomyia bud galls contain multiple larvae, but a G. baccharisella stem gall contains only a single caterpillar. The larvae in the bud galls don’t produce frass (insect poop). I’m not sure what happens to their waste; either they don’t emit any, or it somehow is excreted and carried away by the plant. That latter explanation seems kind of unlikely, but I don’t actually know much about insect/gall interactions, and over evolutionary time scales gall inducers and their host plants have evolved pretty complex relationships.

The caterpillar in the stem gall does produce frass, which accumulates inside the gall. When the caterpillar gets old enough it chews its way out and drops to the ground to complete its development. But now there is a convenient hole in the gall (you can see it in each of the galls pictured above, meaning both of those galls have already lost their original caterpillar), and a bunch of other organisms move in. Colonies of fungi grow on the frass, and fungus mites that eat the fungi, and other creatures that prey on or parasitize the mites. There are whole little worlds in there, and that’s just one type of gall on one type of plant.

When I give in to the temptation to talk about plant galls during docent tours at the marsh, someone usually asks about the nature of the relationship. Are the gall inducers harming the plant? Helping it? And what they’re really asking is, are these good bugs or bad bugs?

It’s a good question. Looking strictly from the perspective of the plant, the gall inducers are harmful. In parts of Australia, where groundsel bush (a close relative of coyote brush) is an invasive weed, R. californica has been imported as a biological control, because the bud galls take the place of flowers, reducing the plant’s reproductive success. In effect, R. californica harnesses the plant’s activity and channels it into producing more R. californica midges, rather than producing more coyote brush.

But the plant’s perspective isn’t the only one. From the point of view of the larger ecosystem, gall inducers are just doing what nearly every other organism has done before it: Finding a niche in the pre-existing biome within which it can survive, adding one more layer to the mind-bogglingly rich assembly of interrelated living things that make up all life.

From that perspective, what gall inducers do is awesome and cool. Certainly the fungus mites that specialize in living inside old G. baccharisella galls would say so, if you could ask them, as would the dozen or more species of parasitic wasps that prey on R. californica, or the hyperparasites that prey on those parasites, or the specialized bacteria that live in the guts of those hyperparasites, and so on, as far as human curiosity can take you. The more I learn about this, the more I believe that people like James Lovelock and the late Lynn Margulis were on the right track in arguing that we spend too much of our time focused on the organism as the most meaningful level of biological organization. We also need to think about life as a whole.

One other thing I liked about Solstice Canyon: Its parking lot was nearly full, but it’s a small lot, and the people who were there were really nice. I think the fact that it’s kind of hidden away on a side road means you’re only going to get people who make a point of seeking it out, and that selects for a certain kind of visitor.

At one point I was standing under a big sycamore, trying to see a woodpecker that I could hear drumming. Two people, an older woman and a younger woman who might have been her adult daughter, were standing not far away. I didn’t notice them paying any attention to me, but when I walked past them the younger woman asked me if I’d been looking for the bird.

“What?” I said, not because I hadn’t heard what she said, but because I’m shy, and a dork, and I’d been shocked out of my big-city bubble by a stranger willing to talk to me.

“Were you looking for the bird?”

“Oh, the woodpecker? Yeah. I couldn’t see it, though.”

“I’ll show you,” she said, and walked back a few feet to point out the bird, an acorn woodpecker that was hammering away at the underside of a dead limb.

“Thanks,” I said, and smiled, and she smiled, and we went our separate ways. And maybe it was just me being maudlin from thinking about Yulin’s video, which made me cry when I watched it — because of the music, and the images, and Auden’s words, and Sean’s delivery — but it just seemed like a really nice thing of that woman to do, noticing that I’d been looking for the bird, and helping me see it.

tl;dr: I had a really nice time at Solstice Canyon, and I’m happy I followed Yulin’s recommendation to visit it.

This is guest post, written by the great Arachnologist & Blogger, Catherine Scott. You can find her blogging over at spiderbytes. People seem to have a particular fear mixed with fascination when it comes to venomous animals, and whenever I talk about my work with black widows I am invariably asked questions like, “have you been bitten yet?” The answer is, of course, no. Spiders alm …

I’ve been working on my own arachnophobia for a long time. Black widows (which live in our woodpile, and occasionally show up when we’re trying to gain ground on the junk in the garage) are kind of my last frontier.